Apparatus for control of highway crossing signals



R. A. M CANN Feb. 1, 1944 Filed Aprii 25, 1942 2 Sheets-Sheet l 9 1% MM 1% w 3 0 0 7 V. P M 5 6 3 Gm ?|.!.l.I-| L c f, i 5 0 m 0\ 1 III. 0 1 2 I n 0 P I r. G 2 2 a H IV I K m -1 K M u NW f 1 G fl W0 am @E 4 1% fl [NVAWTGE 20/20/27 Feb. 1, 1944. McCANN 2,340,816

APPARATUS FOR CONTROL OF HIGHWAY CROSSING SIGNALS Filed April 25, 1942 2 Sheets-Sheet 2y we I L-+- i #1 Cafe ()7 G/fi 51 #9011012 (8132 i9 [NI [M2 012 [/19 Ari- 0mg? Patented Feb. 1, 1944 APPARATUS FOR CONTROL OF HIGHWAY CROSSING SIGNALS Ronald A. McCann, Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April 25, 1942, Serial No. 440,520

6 Claims.

My invention relates to apparatus for control of highway crossing signals, and more particu: larly to apparatus for control of warning signals associated with a highway crossing gate.

Highway crossing gates are frequently controlled automatically by railway traific and the warning signals, either visual or audible, or both, associated therewith are usually controlled by the same approach track circuit that controls th gates. When this is so, the warning signals are operated only when the gates are being lowered due to a train approaching the highway crossing, and the lowering of a gate for any other reason, such as an inspection test, failure of the gate mechanism or failure of a control circuit, may not be accompanied by a warning signal, with the result that highway users may be given no warning and the gate arm may be lowered directly in front of or on top of a highway vehicle.

A feature of my invention is the provision of improved means for control of a warning signal associated with a highway crossing gate and wherewith operation of the warning signal when the gate arm is being lowered for any reason is assured.

Another feature of my invention is the provision of improved means for operating a warning signal independent of the approach track circuit that governs a highway crossing gate.

Other features and objects of my invention will appear as the specification progresses.

I shall describe two forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. l is a diagrammatic view showing one form of apparatus embodying the invention when used with a gate mechanism provided with a slot magnet having circuit; controlling contacts attached to its armature. Fig. 2 is a diagrammatic view showing another form of apparatus embodying my invention when used with a gate mechanism controlled over contacts of an associated control relay. In each of the two views like reference characters are used to designate similar parts.

It will be understood that my invention is not limited to apparatus for a warning signal at a highway crossing gate automatically operated, but is useful when the gate is manually controlled, or when the gate is controlled in part manually and in part by railway traffic. Also the invention is not limited to gates that are gravity biased to the lowered position and motor operated to the raised position, but is useful where the gate is power operated both up and down.

Referring to Fig. 1, the reference characters I a and Ib designate the track rails of a railway intersected at grade by a highway H and at which intersection two highway crossing gates GI and G2 are located. The track rails Ia and Ib are formed by the usual insulated rail joints with two track sections DE and E-F, section D-E extending to the left of highway H as viewed in the drawings, and section E-F extending to the right of the highway. Each section D-E and E-F is provided with a track circuit which includes a current source, such as a battery I0, connected across the rails at one end of the section, and a winding of an interlocking relay IR connected across the rails at the other end of the section, winding I I of relay IR being included inthe track circuit of section D-E and winding I2 of relay IR, being included in the track circult of section E-F. The connections of windings II and I2 of relay IR to the track rails are those commonly used to provide the so-called extended-shunt protection, and these connections need not be described in detail since they form no part of my invention.

The highway crossing gates GI and G2 are shown conventionally and are located one on each side of the railway track and are operated in a manner such that the respective gate arms I3 and I4 are moved between a lowered position where the arm extends horizontally across at least a portion of highway H to obstruct highway traffic approaching the intersection, and a raised position where the arm extends substantially vertically to clear highway traffic. Each crossing gate GI and G2 is provided with an operating mechanism which may be any one of several constructions, and preferably the two mechanisms are of like construction. In the present embodiment of my invention, the gate mechanism is similar to that shown and described in Letters Patent of the United States No. 1,138,087, granted May 4, 1915 to John P. Coleman, for Railway signals. In the present application the gate arm is an extended form of the semaphore of the patent. The mechanism and control means for gate GI only is shown in Fig. '1, for the sake of simplicity, since that for gate G2 would be but a duplication of that for gate GI.

The gate GI mechanism includes as essential elements, a motor MI, a slot magnet SM and a circuit controller CI. Motor Ml, which comprises an armature I5 anda field winding I6 is operatively connected by suitable drive mechanism not shown, to the gate arm I 3, arm l3 being biased by gravity to its lowered position and driven to its raised position when motor MI is energized. In the following description the lowered position of the gate arm will be considered as a zero degree position, and the raised position of the arm will be considered as a '90 degree position.

Slot magnet SM includes a holding winding I1 and a pick-up winding IS, the arrangement being such that energization of both windings H and I8 is required to pick up the armature of the slot magnet, but that once the armature is picked up, then energization. of holding winding I! alone is suflicient to retain the armature picked up. When the armature of the slot magnet SM is picked up, it latches the gate mechanism at the 90 degree position. Furthermore, slot magnet SM is provided with circuit controlling contacts which are attached to its armature i-n'the usual well-known manner.

Circuit cont-roller C! is ,operatively connected with the mechanism for governing circuit controlling contacts accord-mg to the position of the mechanism, three contacts 4, I and 9 being shown conventionally and operated according to the legends placed in the drawings.

A warning signal is associated with gate GI and as shown in Fig. 1, it is an audible signal a combination of a visual signal and an audible signal may be used. Bell BI is provided with two operating circuits, a first one of which passes from terminal B of any convenient source of current, such as a battery not shown, through either full-down 'fiagman contact 22 of relay IR or front fiagman contact 20 and full-down contact 23 of relay IR, contact 7 of controller CI of the gate mechanism, and the winding of bell Bl to terminal of the source of current. The second operating circuit is from terminal B, through contact 4 of controller Cl, back contact 24 of slot magnet SM, controller contact I, and winding of bell Bl to terminal C. It is apparent that bell B! will be operated whenever a train approaching the intersection releases either winding of the interlocking relay IR, and also whenever slot magnet SM is released to close back contact 24, operation of the bell due to the release of magnet SM being independent of the operation effected by interlocking relay IR.

The apparatus also includes a slow release control relay XR which is provided with a circuit including in series the two front flagman contacts 19 and 2B of interlocking relay 1R. Relay XR in turn controls at its front contact 2| simple energizing circuits for windings I1 and I8 of the slot magnet SM, the circuit for winding l8 also including contact 9 of controller C I.

Normally, that is, when both track sections D-E and EF are unoccupied, both windings H and I! of interlocking relay IR are energized, causing control relay XR and in turn the holding winding H of slot magnet SM to be energized with the result that the gate is latched at its 90 degree position. Warning bell BI is now silent because both of its operating circuits are open. When a train approaching the intersection enters either section DE or E-F, releasing either winding H or l2 of relay IR, the closing of full-down contact 22 or 23 of relay IR will complete the first operating circuit for bell BI and the bell will be sounded as a warning to highway users of the approach of the train and that the gate is about to be lowered. Control relay XB is also deenergized upon the opening of either front contact [9 or 20 of the interlocking relay, and relay XR is released at the end of its slow release period to open the energizing circuit of holding winding I 1 of slot magnet SM so that the gate then moves to its lowered position. Release of slot magnet SM closes at back contact 24 the second operating circuit for bell Bl but this second circuit performs no useful function at this time because the bell is already being operated over its first circuit. It is to be pointed out that when the gate arm is lowered to nearly the zero degree position, operation of the bell is discontinued due to the opening of controller contact 7. When the train clears the intersection, the previously deenergized winding II or l2 of the interlocking relay is reenergized to close its front flagman contact 19 or 20 so that relay XR is reenergized causing both windings l1 and I8 of the slot magnet SM to be energized and the armature of the slot magnet to be picked up. A motor operating circuit is now completed from terminal B through controller contact 4, front contacts 25 and 26 in multiple of slot magnet SM, and armature l5 and field winding 15 of motor M1 to terminal 0, so that the motor is operated as required to raise the gate. At the 89 degree position, the motor operating circuit is opened at contact 4 and the circuit for winding 18 of slot magnet SM is opened at contact 9, but the gate is latched in the raised position due to the energization of holding Winding l1.

Lowering of gate G1 due to the release of slot magnet SM for any reason other than the control effected by a train through the track circuits is accompanied by an operation of the warning signal, bell BI being operated through its second circuit including back contact 24 of slot magnet SM. Deenergization of slot magnet SM and a lowering of the gate while the track circuits are unoccupied and relay IR is picked up may be brought about due to a test operation, or due to a failure of a control circuit or of the gate mechanism.

It is to be observed thatmotor M! is driven backward during the lowering of the gate and regenerative braking provided through a low re-' sistance shunt path completed through the motor at back contacts 36 and 31 in multiple of slot magnet SM.

It is to be seen therefore that with the apparatus disclosed in Fig. 1, the warning signal BI is operated by a first circuit when the gate is lowered due to the approach of a train, and is operated by a second circuit when the gate is lowered due to some failure of the apparatus or other condition, the operation by the second circuit being independent of the track circuit control.

Referring to Fig. 2, the track circuits are the same as in Fig. 1. Furthermore, gate GI mechanism of Fig. 2 is similar to that of Fig. 1 except that the contacts attached to the armature of the slot magnet SM are omitted, additional contacts are included in controller Cl, and the motor Ml is provided with a so-called snubbing relay SR for control of a low resistance shunt path, connected across the motor for regenerative braking during the lowering of the gate arm. The apparatus of Fig. 2 includes three control relays XR, TPR and GPR. Relay XR is controlled over front fiagman contacts l9 and 20 of relay IR as in Fig. 1, but relay XR of Fig. 2 is preferably not of the slow release type. Relay TPR is a slow release repeater relay controlled over a simple circuit including in series the front flagman contacts 21 and 28 of interlocking relay IR. Relay GPR is controlled by a circuit passing from terminal B, through front contacts 29 and 30 in multiple of relay XR, contact 2 of controller Cl, and Winding of relay GPR to terminal C.

Normally, that is, when the track circuits are unoccupied by a train approaching the intersection, control relays XR, 'IPR and GPR are all picked up. The front contact 3| of relay TPR then completes a simple circuit for holding winding ll of slot magnet SM so that the gate mechaism is latched at its 90 degree position. Bell BI is normally silent.

A train approaching the intersection of Fig. 2 from either direction causes the corresponding winding of relay IR to be deenergized, and the closing of either full-down contact 22 or 23 of relay IR completes a first operating circuit for bell Bl through contact 1, so that the bell is sounded as a warning that the gate is about to be lowered. Relay XR is deenergized and releases to open the circuit for relay GPR and to open a motor operating circuit to be shortly explained. Relay TPR is also deenergized and releases at the end of its slow release period to deenergize the slot magnet SM and permit the gate to gravitate to its lowered position. Motor MI is driven backwards during the downward movement of the gate and regenerative braking of the gate mechanism is provided due to a low resistance shunt path completed through back contact 32 of relay SR, contact of controller Cl, and a portion of a resistor 33. Just before the zero degree position of the gate arm is reached, the operation of the bell BI is discontinued due to contact I opening the operating circuit for the .bell. When the train clears the intersection to permit relay IR to reclose its fiagman contacts, the two relays XR and TPR are reenergized and picked up. The picking up of relay TPR energizes winding I! of slot magnet SM. The picking up of relay XR to close its front contacts 29 and 39 completes a motor operating circuit through contact 4 of controller CI, winding of relay SR, and armature l5 and field winding H5 or motor Ml to terminal C of the current source. Relay SR is thus energized and picked up to open back contact 32 and so remove the w resistance path across the motor MI, and the motor is operated to raise the gate arm. At the 86 degree position of the movement of the gate, contacts 2 and 3 are closed, the closing of contact 2 completing the circuit for relay GPR to pick up that relay. The closing of contact 3 completes the circuit for winding l8 of slot magnet SM, the circuit passing from terminal B through front contacts 29 and 30 in multiple of relay XR, contacts 4 and 3 in seriesand winding l8 to terminal C. Both windings I] and I8 of the slot magnet being now energized, its armature is picked up so that the gate mechanism is latched in the 90 degree position when the motor operating circuit and the circuit for winding 18 are opened at contact 4 of the controller CI.

In the event slot magnet SM becomes deenergized for any reason other than the control effected by interlocking relay IR, the gate starts to gravitate to its lowered position, and at the 86 degree position relay GPR is released to close back contact 34 and complete a second operating circuit for bell Bl, such operating circuit also including back contact 35 of relay SR, and contact 1 of controller Cl. Thus bell BI is sounded as a warning indication that the gate is being lowered whenever the magnet SM is deenergized to unlatch the gate mechanism.

It is to be pointed out that in both Figs. 1 and 2, bell BI is silent during the operation of raising the gate. In Fig. 1, the first operating circuit for bell BI is held open at the back contacts 22 and 23 of relay IR and the second circuit is held open at back contact 24 of slot magnet SM during this operation. In Fig. 2, the first operating circuit for bell BI is held open at the back contacts of relay IR, the same as in Fig. 1, and the second operating circuit is held open at back contact 35 of relay SR. It is to be observed that in Fig. 2,

if it is desired that the bell Bl be sounded during:

the raising of the gate, the back contact 35 of relay SR would be omitted from the second operating circuit for the bell and the bell would be oper-' ated by the second operating circuit until the 86' degree position of the movement is reached, at which point relay GPR is picked up to open the bell circuit at back contact 34.

The apparatus disclosed in Fig. 2 has the same desirable advantages as the apparatus of Fig. 1, in that the warning signal is operated when the associated gate is being lowered irrespective of the circumstances that cause the gate to be lowered. Consequently the possibility of the gate arm being lowered immediately in front of oron top of a highway vehicle is minimized by the apparatus here disclosed.

Although I have herein shown and describedbut two forms of highway crossing signal control apparatus embodying my invention, it is understood that various changes and modifications may be made therein Within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a highway crossing gate located at an intersection of a railway and a highway, a warning signal located to provide at times a warning indication to highway trafiic opproaching said intersection, electromagnetic means to govern said gate to its clear or obstructing position according as said electromagnetic means is energized or deenergized, circuit means controlled by railway trafiic to energize or deenergize said electromagnetic means according as a train is not or is approaching the intersection, a first operating circuit controlled by said circuit means to operate said signal to give its warning indication when a train approaches the intersection, and a second operating circuit controlled by said electromagnetic means when deenergized to operate said signal to give its warning indication.

2. In combination, a highway crossing gate located at an intersection of a railway and a highway and provided with an arm movable either to a lowered position where it obstructs highway traffic or to a raised position where is clears highway traific, a slot magnet for said gate to latch the arm at its raised position when the magnet is energized and to permit the arm to move to its lowered position when the magnet is deenergized, railway traffic controlled means to energize or deenergize said slot magnet according as a train is not or is approaching said intersection, a warning signal at said intersection active at times to give a Warning indication but normalrailway trafiic controlled means when a train is approaching the intersection to render said signal active, and a second circuit means including a back contact controlled by said slot magnet to render said signal active independent of said railway traffic controlled means.

3. In combination, a highway crossing gate located at an intersection of a railway and a highway and provided with an arm movable to either a lowered position to obstruct highway trafilc or to a raised position to clear highway traific, a slot magnet for said gate, a track circuit including a track relay responsive to railway traffic approaching said intersection, an electric bell at said gate for sounding a warning when the gate arm is being lowered, a first circuit including a front contact of said track relay to energize said slot magnet, a second circuit including a back contact of said track relay to operate said bell, and a third circuit including a back contact of said slot magnet to operate said bell independent of said second circuit.

4. In combination, a highway crossing gate located at an intersection of a railway and a highway and provided with an arm movable to either a lowered position to obstruct highway trafiic or to a raised position to clear highway traffic, a track circuit including a track relay responsive to railway traffic approaching said intersection, an electric bell at said gate to sound an alarm, control relay means, means controlled by said control relay means to retain said gate arm at its raised position when the control relay means is energized and to permit the lowering of the gate arm when the control relay means is deenergized, means including a front contact of said track relay to energize said control relay means, a first operating circuit including a back contact of said track relay to operate said bell, and a second operating circuit including a contact governed by said control relay means when deenergized to operate said bell independent of said first operating circuit.

5. In combination, a highway crossing gate located at an intersection of a railway and a highway and provided with an arm movable to either a lowered position to obstruct highway trafiic or to a raised position to clear highway traflic, a track circuit including a track relay responsive to railway trafiic approaching said intersection, an electric bell, a control relay, motor means governed by said control relay when energized to move the gate arm to its raised position and to permit movement of the arm to its lowered position when said control relay is deenergized. means including a front contact of said track relay to energize said control relay, a first operating circuit including a back contact of said track relay to operate said bell, and a second operating circuit including a contact controlled by said control relay, and a contact governed by said motor means to operate said bell independent of said first operating circuit.

6. In combination, a highway crossing protecting means located at an intersection of a railway and a highway and movable to a first position where it obstructs highway trafiic entering the intersection and a second position where it clears highway tramc, electromagnetic means to govern the movement of said protecting means, a warning signal at said intersection, a track circuit including a track relay responsive to railway traific approaching said intersection. means including a contact of said track relay to control said electromagnetic means to effect the first or the second position of said protecting means according as a train is or is not approaching the intersection, a first operating circuit including a contact of said track relay to operate said warning signal in response to a train approaching'the intersection, and a second operating circuit including a contact governed by said electromagnetic means when conditioned to permit movement of said protecting means to its first position to operate said warning signal independent of said first operating circuit.

RONALD A, McCANN. 

